This heavy weight fabric is 100% spun polyester 385g/m2 that will not shrink under the heat press. Polyester is one of the leading synthetic fibers for sublimation, since it soaks up the dyes and inks very eagerly, leaving you with a beautifully vivid and crisp image transfer. The recommended settings for sublimation are 205 degrees Celsius (400 degrees Fahrenheit) for 60 seconds on medium pressure. These covers can also be used for heat transfer vinyl on a lower heat setting and less press time. This fabric is machine washable. Made in China.